HBY – Rod Hydraulic Buffer Seal

The HBY hydraulic buffer seal, mounted on the pressure side of the piston rod seal, is designed to improve the durability of the piston rod seal by venting the pressure back to the system side. The main parts of the buffer seal are the static lip, dynamic lip, radial slots, and radial channels. The static lip of the seal is optimized with high flexibility to relieve the interstage pressure. The dynamic lip can minimize the friction and backpressure under high-pressure condition. The radial slots of the buffer seal are designed to reduce the risk of blow-by. The radial channels, a vital element in the whole seal structure, facilitate back-pumping and relieve the pressure.

The hydraulic buffer seal is always used together with other rod seals, such as U-cup seal or Y seal, building a “tandem configuration.” The main functions of the buffer seal in the hydraulic system include several aspects. First, it buffers the shock pressure or pressure fluctuations produced by the piston rod of the hydraulic cylinder, easing the backpressure. Second, the seal helps cooling down the temperature, prevents the overheat from transmitting to the seal, and reducing heat generated from the piston rod seal during operation. Third, it reduces the friction resistance caused by the piston rod seal in the hydraulic cylinder. In general, the buffer seal provides adequate lubrication to the piston rod seal or other main seals, and it can enhance the gap extrusion resistance. Thereby, it can extend the durability of the seal element.

In harsh conditions, machines or equipment often encounter dramatic swings in pressure, shock loads in temperature or side loads which affect the operation of the hydraulic system. This factor presents a significant and demanding challenge for the buffer seal. Fortunately, DSH Seals can optimize the buffer seals to match customers’ specific hydraulic application needs. The buffer seals DSH Seals offers are especially suitable for heavy-duty, agricultural machinery, mobile, and industrial hydraulic applications, including bulldozers, earth moving equipment, cranes, dump trucks, motorized shovels, boom extension cylinders, wheel loaders, etc. HBY seals in DSH Seals are designed referring to the designs and applications of NOK’s HBY, DZ’s D-10 series.

Product Features

1. A long service life to minimize maintenance and downtime.

2. No adhesion to the sliding surface.

3. Effective in relieving any pressure built up in the hydraulic system.

4. Excellent abrasion and wear resistance.

5. Providing secondary sealing to reduce the influence of the pressure spikes.

6. Improving the rod seal life.

7. Leak-free performance.

8. Resistant against high temperature and pressure.

9. Low compression set.

10.The unique design of static and dynamic lips for superior performance.

◆◆ NBR / FKM rubber, POM

◆◆ Cushion Ring for Rod – HBY